TOKYO -- Hydrogen is considered a green, next-generation energy source. But achieving the stable hydrogen procurement required to bring the resource to the masses has proved challenging.
Unlike fossil fuels, hydrogen does not emit carbon dioxide: It only produces water when it is burned. It is the lightest of all elements; its calorific value per unit weight is 2.7 times higher than gasoline.
Pure hydrogen is near impossible to find on Earth. It is generally found in combination with oxygen, as water. To get the element alone, researchers have been working on ways to break down substances that include hydrogen molecules.
Hydrogen is widely used in industrial products. For example, it is used to remove sulfur content from crude oil in petroleum refining and to shine the surface of stainless steel. It is also used to solidify fat in lipstick and margarine. Petroleum refiners and steelmakers use most of the hydrogen generated during manufacturing processes at their factories.
Japan's Toyota Motor unveiled a fuel-cell vehicle, which runs on hydrogen, at the end of last year. Honda Motor plans to introduce a similar vehicle during fiscal 2015, which begins next month. Kawasaki Heavy Industries and Mitsubishi Heavy Industries are developing hydrogen power generation technologies.
Japan's largest industrial hydrogen supplier, Iwatani, has a production base for the energy source in an industrial district of Ichihara, Chiba Prefecture. The company liquefies hydrogen by cooling it to minus 253 C, which reduces its volume by 800 times, for transport.
The original hydrogen is a byproduct of making caustic soda at an adjacent factory operated by Asahi Glass. It is sent to Iwatani's factory through a pipeline for purification and liquefaction.
Iwatani has three liquefied hydrogen factories in Japan. "We obtain hydrogen either by using a byproduct of caustic soda or by reforming natural gas (that includes hydrogen)," said an official at the company.
Japan's Institute of Applied Energy estimates that the nation's total annual hydrogen production capacity stands at 35.6 billion normal cu. meters, of which more than 80% is consumed by producers themselves. Normal cubic meters measure volume at an atmospheric pressure of 1 and temperature of 0 C.
Only 6.5 billion normal cu. meters of hydrogen can be supplied outside, an amount that could feed two 1 gigawatt hydrogen power plants. It could also supply some 1.6 million fuel-cell vehicles, equivalent to 3% of the cars on the road in Japan, with fuel.
The institute projects that hydrogen will be in short supply in 2020 or later if no measures are taken.
To solve this problem, Kawasaki Heavy is leading a project to produce a large amount of hydrogen by gasifying lignite, a cheap and low-quality coal produced in southeast Australia, and bring it to Japan. The company aims to start operations on a trial basis in 2020.
Kawasaki Heavy also intends to lower hydrogen sales prices, another challenge facing the Japanese hydrogen industry. "We want to halve the current wholesale price of hydrogen to roughly 30 yen ($0.25) per cubic meter in 2025," says Motohiko Nishimura, senior manager of the Hydrogen Project Department.
Iwatani and JX Nippon Oil & Energy are currently retailing hydrogen for vehicles for less than 100 yen per cubic meter, pushing down fuel costs to similar levels as hybrid vehicles see. Ichiro Uchijima, executive vice president at JX Nippon Oil & Energy, says, "We ignore profitability."
Though hydrogen emits no carbon dioxide when it is used, it does produce the gas during manufacturing.
That prompted major electrical machinery maker Toshiba and the city of Kawasaki to jointly conduct demonstration tests this year to produce emission-free hydrogen from renewable energy sources.
They will store energy produced by solar power in batteries and produce hydrogen by electrolyzing water as needed. The produced hydrogen will be supplied to a fuel cell to make electricity and hot water.
Metawater, Japan's largest supplier of waste water treatment system, will build a plant to obtain hydrogen by reforming biogas made from sewage sludge and supply the resulting product to fuel cells.